As more and more people in the world use their mobile phones (especially smart phones) as a daily necessity for personal communication, as a personal information manager (PIM) and/or for doing business, loss or theft of the phone means not only loss of property but also the potential leak of personal information, client information and/or company information to, and illegal use by, an unauthorised person, even after the loss or theft is reported to the carrier or to the police.
Several measures have been taken to protect the security of mobile phones. For example, SIM-locking the mobile phone to a SIM (subscriber identity module) card may reduce the possibility of the phone being used with another SIM card. Enabling the PIN security feature of a mobile phone ensures that it can only be used if the PIN has been keyed in. Mobile carriers are able to block the use of customers' lost or stolen mobile phones on their network. However, all of these security features are soft, meaning that the security features are not difficult to be unlocked by hackers or crackers and therefore offer limited protection to the information stored in the phone. High-end smart phones are targeted by phone thieves in some countries because of their re-use values, at least as a PIM or an entertainment device, for instance as a game-player, a camera and/or a music player in offline mode.